net/hub.c

   1 /*
   2  * Hub net client
   3  *
   4  * Copyright IBM, Corp. 2012
   5  *
   6  * Authors:
   7  *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
   8  *  Zhi Yong Wu       <wuzhy@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
  11  * See the COPYING.LIB file in the top-level directory.
  12  *
  13  */
  14
  15 #include "monitor/monitor.h"
  16 #include "net/net.h"
  17 #include "clients.h"
  18 #include "hub.h"
  19 #include "qemu/iov.h"
  20
  21 /*
  22  * A hub broadcasts incoming packets to all its ports except the source port.
  23  * Hubs can be used to provide independent network segments, also confusingly
  24  * named the QEMU 'vlan' feature.
  25  */
  26
  27 typedef struct NetHub NetHub;
  28
  29 typedef struct NetHubPort {
  30     NetClientState nc;
  31     QLIST_ENTRY(NetHubPort) next;
  32     NetHub *hub;
  33     int id;
  34 } NetHubPort;
  35
  36 struct NetHub {
  37     int id;
  38     QLIST_ENTRY(NetHub) next;
  39     int num_ports;
  40     QLIST_HEAD(, NetHubPort) ports;
  41 };
  42
  43 static QLIST_HEAD(, NetHub) hubs = QLIST_HEAD_INITIALIZER(&hubs);
  44
  45 static ssize_t net_hub_receive(NetHub *hub, NetHubPort *source_port,
  46                                const uint8_t *buf, size_t len)
  47 {
  48     NetHubPort *port;
  49
  50     QLIST_FOREACH(port, &hub->ports, next) {
  51         if (port == source_port) {
  52             continue;
  53         }
  54
  55         qemu_send_packet(&port->nc, buf, len);
  56     }
  57     return len;
  58 }
  59
  60 static ssize_t net_hub_receive_iov(NetHub *hub, NetHubPort *source_port,
  61                                    const struct iovec *iov, int iovcnt)
  62 {
  63     NetHubPort *port;
  64     ssize_t len = iov_size(iov, iovcnt);
  65
  66     QLIST_FOREACH(port, &hub->ports, next) {
  67         if (port == source_port) {
  68             continue;
  69         }
  70
  71         qemu_sendv_packet(&port->nc, iov, iovcnt);
  72     }
  73     return len;
  74 }
  75
  76 static NetHub *net_hub_new(int id)
  77 {
  78     NetHub *hub;
  79
  80     hub = g_malloc(sizeof(*hub));
  81     hub->id = id;
  82     hub->num_ports = 0;
  83     QLIST_INIT(&hub->ports);
  84
  85     QLIST_INSERT_HEAD(&hubs, hub, next);
  86
  87     return hub;
  88 }
  89
  90 static int net_hub_port_can_receive(NetClientState *nc)
  91 {
  92     NetHubPort *port;
  93     NetHubPort *src_port = DO_UPCAST(NetHubPort, nc, nc);
  94     NetHub *hub = src_port->hub;
  95
  96     QLIST_FOREACH(port, &hub->ports, next) {
  97         if (port == src_port) {
  98             continue;
  99         }
 100
 101         if (qemu_can_send_packet(&port->nc)) {
 102             return 1;
 103         }
 104     }
 105
 106     return 0;
 107 }
 108
 109 static ssize_t net_hub_port_receive(NetClientState *nc,
 110                                     const uint8_t *buf, size_t len)
 111 {
 112     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
 113
 114     return net_hub_receive(port->hub, port, buf, len);
 115 }
 116
 117 static ssize_t net_hub_port_receive_iov(NetClientState *nc,
 118                                         const struct iovec *iov, int iovcnt)
 119 {
 120     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
 121
 122     return net_hub_receive_iov(port->hub, port, iov, iovcnt);
 123 }
 124
 125 static void net_hub_port_cleanup(NetClientState *nc)
 126 {
 127     NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
 128
 129     QLIST_REMOVE(port, next);
 130 }
 131
 132 static NetClientInfo net_hub_port_info = {
 133     .type = NET_CLIENT_OPTIONS_KIND_HUBPORT,
 134     .size = sizeof(NetHubPort),
 135     .can_receive = net_hub_port_can_receive,
 136     .receive = net_hub_port_receive,
 137     .receive_iov = net_hub_port_receive_iov,
 138     .cleanup = net_hub_port_cleanup,
 139 };
 140
 141 static NetHubPort *net_hub_port_new(NetHub *hub, const char *name)
 142 {
 143     NetClientState *nc;
 144     NetHubPort *port;
 145     int id = hub->num_ports++;
 146     char default_name[128];
 147
 148     if (!name) {
 149         snprintf(default_name, sizeof(default_name),
 150                  "hub%dport%d", hub->id, id);
 151         name = default_name;
 152     }
 153
 154     nc = qemu_new_net_client(&net_hub_port_info, NULL, "hub", name);
 155     port = DO_UPCAST(NetHubPort, nc, nc);
 156     port->id = id;
 157     port->hub = hub;
 158
 159     QLIST_INSERT_HEAD(&hub->ports, port, next);
 160
 161     return port;
 162 }
 163
 164 /**
 165  * Create a port on a given hub
 166  * @name: Net client name or NULL for default name.
 167  *
 168  * If there is no existing hub with the given id then a new hub is created.
 169  */
 170 NetClientState *net_hub_add_port(int hub_id, const char *name)
 171 {
 172     NetHub *hub;
 173     NetHubPort *port;
 174
 175     QLIST_FOREACH(hub, &hubs, next) {
 176         if (hub->id == hub_id) {
 177             break;
 178         }
 179     }
 180
 181     if (!hub) {
 182         hub = net_hub_new(hub_id);
 183     }
 184
 185     port = net_hub_port_new(hub, name);
 186     return &port->nc;
 187 }
 188
 189 /**
 190  * Find a specific client on a hub
 191  */
 192 NetClientState *net_hub_find_client_by_name(int hub_id, const char *name)
 193 {
 194     NetHub *hub;
 195     NetHubPort *port;
 196     NetClientState *peer;
 197
 198     QLIST_FOREACH(hub, &hubs, next) {
 199         if (hub->id == hub_id) {
 200             QLIST_FOREACH(port, &hub->ports, next) {
 201                 peer = port->nc.peer;
 202
 203                 if (peer && strcmp(peer->name, name) == 0) {
 204                     return peer;
 205                 }
 206             }
 207         }
 208     }
 209     return NULL;
 210 }
 211
 212 /**
 213  * Find a available port on a hub; otherwise create one new port
 214  */
 215 NetClientState *net_hub_port_find(int hub_id)
 216 {
 217     NetHub *hub;
 218     NetHubPort *port;
 219     NetClientState *nc;
 220
 221     QLIST_FOREACH(hub, &hubs, next) {
 222         if (hub->id == hub_id) {
 223             QLIST_FOREACH(port, &hub->ports, next) {
 224                 nc = port->nc.peer;
 225                 if (!nc) {
 226                     return &(port->nc);
 227                 }
 228             }
 229             break;
 230         }
 231     }
 232
 233     nc = net_hub_add_port(hub_id, NULL);
 234     return nc;
 235 }
 236
 237 /**
 238  * Print hub configuration
 239  */
 240 void net_hub_info(Monitor *mon)
 241 {
 242     NetHub *hub;
 243     NetHubPort *port;
 244
 245     QLIST_FOREACH(hub, &hubs, next) {
 246         monitor_printf(mon, "hub %d\n", hub->id);
 247         QLIST_FOREACH(port, &hub->ports, next) {
 248             if (port->nc.peer) {
 249                 monitor_printf(mon, " \\ ");
 250                 print_net_client(mon, port->nc.peer);
 251             }
 252         }
 253     }
 254 }
 255
 256 /**
 257  * Get the hub id that a client is connected to
 258  *
 259  * @id: Pointer for hub id output, may be NULL
 260  */
 261 int net_hub_id_for_client(NetClientState *nc, int *id)
 262 {
 263     NetHubPort *port;
 264
 265     if (nc->info->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
 266         port = DO_UPCAST(NetHubPort, nc, nc);
 267     } else if (nc->peer != NULL && nc->peer->info->type ==
 268             NET_CLIENT_OPTIONS_KIND_HUBPORT) {
 269         port = DO_UPCAST(NetHubPort, nc, nc->peer);
 270     } else {
 271         return -ENOENT;
 272     }
 273
 274     if (id) {
 275         *id = port->hub->id;
 276     }
 277     return 0;
 278 }
 279
 280 int net_init_hubport(const NetClientOptions *opts, const char *name,
 281                      NetClientState *peer)
 282 {
 283     const NetdevHubPortOptions *hubport;
 284
 285     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_HUBPORT);
 286     hubport = opts->hubport;
 287
 288     /* Treat hub port like a backend, NIC must be the one to peer */
 289     if (peer) {
 290         return -EINVAL;
 291     }
 292
 293     net_hub_add_port(hubport->hubid, name);
 294     return 0;
 295 }
 296
 297 /**
 298  * Warn if hub configurations are likely wrong
 299  */
 300 void net_hub_check_clients(void)
 301 {
 302     NetHub *hub;
 303     NetHubPort *port;
 304     NetClientState *peer;
 305
 306     QLIST_FOREACH(hub, &hubs, next) {
 307         int has_nic = 0, has_host_dev = 0;
 308
 309         QLIST_FOREACH(port, &hub->ports, next) {
 310             peer = port->nc.peer;
 311             if (!peer) {
 312                 fprintf(stderr, "Warning: hub port %s has no peer\n",
 313                         port->nc.name);
 314                 continue;
 315             }
 316
 317             switch (peer->info->type) {
 318             case NET_CLIENT_OPTIONS_KIND_NIC:
 319                 has_nic = 1;
 320                 break;
 321             case NET_CLIENT_OPTIONS_KIND_USER:
 322             case NET_CLIENT_OPTIONS_KIND_TAP:
 323             case NET_CLIENT_OPTIONS_KIND_SOCKET:
 324             case NET_CLIENT_OPTIONS_KIND_VDE:
 325                 has_host_dev = 1;
 326                 break;
 327             default:
 328                 break;
 329             }
 330         }
 331         if (has_host_dev && !has_nic) {
 332             fprintf(stderr, "Warning: vlan %d with no nics\n", hub->id);
 333         }
 334         if (has_nic && !has_host_dev) {
 335             fprintf(stderr,
 336                     "Warning: vlan %d is not connected to host network\n",
 337                     hub->id);
 338         }
 339     }
 340 }